I agree with your summation of throwing stuff for Deadpool & Wolverine. LIke I have stated previously, zany, a.k.a. quirky and eccentric, is central to a Deadpool plot.
I disagree with it being similar to what you described in Age of Ultron. Yes. Initially, Wanda and Pietro hated Stark, Wanda moreso than her brother. Their mutual animosity felt for Iron Man and his compatriots peaked during their initial fight at the adamantium exchange.
However, the plot did not have the twins flippantly switch emotional gears afterwards. Their feelings changed, shifted, became more introspective as the movie's action phase continued to build as:
- Wanda getting a mental glimpse of Ultron's plan reading The Vision's mind
- Both siblings watching their enemies fight their revenge partner while extracting The Vision
The plot exposed the twins to the same truth that the audience already knew. Ultron's true plans would be far more devastating to all of humanity than the war and horrors they suffered in part because of Stark's weaponry. They experienced the reality of sticking with the story's antagonist. It was not presented to them in secondhand fashion, thus requiring zero need to convince them which side to take.
Wanda was still not completely on The Avengers side when Cap told her Stark would take care of The Vision's containment pod. Her bias opinion of Tony's intentions prompted her to tell Steve his assumption of what HIS friend would do was wrong. Wanda did not just fall in line with the people she now needed. She lectured an Avenger of the inherit danger of trusting Stark since she knew his programming was Ultron's twisted version of him
Then the twins listened to The Vision's rationalizing with The Avengers of Ultron's plan. That experience cut even further and deeper into their previous feelings of revenge.
Understandably, the bulk of what happened to this point was focused interactions between team members. It is an Avengers movie, not a Maximoff movie, lol. The team retreating to Clint's farm to regroup took up a notable chunk of film time. That aside, the plot demonstrated how and why the twins' allegiance switched in logical progression that fit neatly within its presentation as it was nearing the eventual climax.
The cave scene? I found it essential. The original Avengers movie taught the team that Earth must fend itself from external threats but they did not know just how much of a threat existed. The AUDIENCE knew the real threat was Thanos. Ultron was a puppet in Thanos' plan. And what was Thanos' ultimate plan?
Answer: To gain possession of the Infinity Gauntlet and enact his insane universal plan of balancing want and need.
That is what the cave scene accomplishes. Omitting it does not provide the team any clue of the horrific danger they could face in
Avengers: Infinity War. In short, it is a tie-in to what was to come.
That said, The Marvels did come close for me.
